Its interesting. We can both look at a landscape and agree there’s two mountains in the distance and a forest in front, and can agree on a thousand further details like if the mountains are barren or snow-topped. But only when it comes to colour can we doubt whether what the other person sees is what we see. To be fair, the artist Monet did that experiment on himself. Painted a scene with one eye open and the next day with the other. Details are pretty much the same, but the spectrum is pretty different